It represents cosine angle between two vectors. It measures similarity rather than distance or dissimilarity. Thus, higher value of Angular separation indicates the two objects are similar. The value of angular separation is [-1, 1] similar to cosine. It is often called as Coefficient of Correlation. We need to define
Point A has coordinate (0, 3, 4, 5) and point B has coordinate (7, 6, 3, -1).
The angular separation between point A and B is
How does Angular Separation name come from?
From vector algebra we remember that cosine angle between two vectors can be represented as dot product divided by length of the two vectors
The length of a vector (sometimes called modulus) is the root of square of its coordinate
Putting the two together, we get
Changing the notation of vectors into coordinate, we get angular separation formula
Preferable reference for this tutorial is
Teknomo, Kardi. Similarity Measurement. http:\\people.revoledu.com\kardi\ tutorial\Similarity\
© 2006 Kardi Teknomo. All Rights Reserved.
Designed by CNV Media